1. Technical Field
This invention relates generally to multi-node computer systems, which are computer systems in which there is more than one node having a processor, memory, and so on, and more particularly to managing hardware events generated by the nodes of such systems.
2. Description of the Prior Art
In a computer system, various hardware generate events that need to be handled. For example, the Advanced Configuration and Power Interface (ACPI) specification provides for a power management and configuration mechanism. In ACPI-compatible computer systems with ACPI-compatible hardware, the systems themselves can be turned on and off in response to internal and external events, and the specific pieces of hardware can also be managed from a power vantage point. A network card in a low-power mode, for instance, may generate an event when it receives a packet of data from the network to which it is attached, and wake up from the low-power mode. This event is received by the computer system of which the network card is a part, so that, for example, the computer system may itself exit a lower-power mode it had previously entered. Another type of event is the hot-plug event, which results from a hardware card being inserted into or removed from a computer system while the system is on.
A disadvantage to ACPI events, as well as other types of hardware events, is that they presume handling thereof by the computer system of which the hardware generating the events are a part. That is, frequently hardware events are specified in accordance with an architecture that is multi-node system unaware, and thus presumes that the architecture is a single-node system. In multi-node computer systems, there are a number of nodes, each having its own processors, memory, and so on, over which processing is distributed. Furthermore, chipsets that implement ACPI event hardware are themselves typically multi-node unaware. Operating systems that are ACPI aware generally presume a single instance of ACPI event hardware in the system, and are also usually unaware of replicated ACPI event hardware.
Current hardware event handling architectures, therefore, frequently assume that the events generated within a given remote node of a multi-node computer system will be handled by that node. There is no mechanism, for instance, for a primary or boot node of the system to receive notification of the event, nor for this node to handle the event and to direct the remote node as to how to process the event. There is also no mechanism provided by standard ACPI event hardware to inform an operating system on which node an event occurred. This is problematic, because operating system policies for handling hardware then assume a single instance of ACPI event hardware for the entire system. However, this assumption does not hold true for a multi-node system designed around standard ACPI event hardware. For these described reasons, as well as other reasons, there is a need for the present invention.